Conjugate filaments apparatus

ABSTRACT

Process and apparatus for sheath/core conjugate filaments in which a jet of a first fiber-forming polymer is forced into confined space, second fibre-forming polymer is forced around first polymer from one side and polymers are extruded to form filaments. Preferably the ducts for first and second polymers are formed in part by appropriate apertures in metal shims.

United States Patent 1191 Cheetham Jan. 22, 1974 CONJUGATE FILAMENTSAPPARATUS [75] Inventor: John Laurence Cheetham,

Harrogate, England [73] Assignee: Imperial Chemical Industries Limited,London, England [22] Filed: Apr. 13, 1972 [21] App]. No.: 243,878

3,559,237 2/1971 Biggelaar et a1. 425/198 3,613,170 10/1971 Soda et a1.425/463 3,204,290 9/1965 Crompton 425/463 3,418,200 12/1968 Tanner161/177 3,700,545 10/1972 Matsui et al. 161/175 FOREIGN PATENTS ORAPPLICATIONS 43/11821 5/1968 Japan 264/171 44/22523 9/1969 Japan 425/463Primary Examiner-Jay H. Woo Attorney, Agent, or FirmThomas J. Morgan eta1.

[57] ABSTRACT Process and apparatus for sheath/core conjugate fila- 156]References Cited ments in which a jet of a first fiber-forming polymeris UNITED STATES PATENTS forced into confined space, secondfibre-forming poly- 2,815,532 12/1957 Braunlich 425/463 mer is forcedaround first P y from one Side and 3,017,686 H1962 Breen et a1. 264/171p lymers a trud d t f rm filaments. Preferably 3,075,241 H1963 Dietzschet a1. 425/463 the ducts for first and second polymers are formed in3,439,382 4/1969 Sluijters 425/463 part by appropriate apertures inmetal shims. 3,500,498 3/1970 Fukuma et a1.... 425/133 3,540,080 11/1970Goossens 425/133 1 Claim, 9 Drawing Figures 8, 1.1 W 8 I 1 l I 10 5 5 1073 74 9 5 5 9 PATENTEDJAN 22 I974 3 787 l 62 sum 1 nr 4 WWW m4 smart aor 4 b, .XM

Fll

W 5 m/ O CONJUGATE FILAMENTS APPARATUS The present invention relates tothe manufacture of sheath/core conjugate filaments.

According to the present invention we provide a process for themanufacture of a sheath/core conjugate filament wherein a jet of a firstfiber-forming polymer is forced into a confined space communicating witha spinning orifice, a second fiber-forming polymer is forced into saidconfined space from one side of said jet of said first fiber-formingpolymer and said first and second polymers are allowed to flow insheath/core relationship through said spinning orifice with formation ofa sheath/core filament.

Preferably said confined space is elongated, with the entry points forthe first and second polymers at one end and the communication with saidspinning orifice at the other end. Conveniently said confined space isessentially cylindrical with length greater than its diameter.

Preferably the second fiber-forming polymer is forced into said confinedspace in the form of a thin sheet of flow, the width of the sheet beinggreater than the width of the confined space at the level of entry ofthe second fiber-forming polymer. Preferably the confined space iselongated in the direction at right angles to the plane of the thinsheet of flow of the second polymer.

Although the second fiber-forming polymer is forced into the confinedspace from one side, it should be free to surround the jet of the firstfiber-forming polymer at an early stage in its transit through theconfined space. This may be facilitated by the provision of a wideningof the confined space at the point of entry of the second polymer. Suchwidening should preferably be at the upstream end of the confined space.

According to our invention we also provide an apparatus suitable forcarrying out the process of our invention, comprising a confined spacewith exit to a spinneret aperture at one end, a first entry aperturesubstantiably at the end distant from the exit, and a second entryaperture to one side of the first entry aperture.

Preferably the confined space is elongated in the direction from entryaperture to spinneret aperture. Conveniently the confined space ifessentially cylindrical with length greater than its diameter.Preferably the second entry aperture is in communication with theconfined space by way of a radially enlarged portion of the confinedspace near the end of the confined space preferably where the firstentry aperture is situated.

A plurality of confined spaces with apurtenances according to ourinvention may be combined in a single apparatus and this may be used toproduce simultaneously a plurality of conjugate filaments.

The apparatus according to our invention may advantageously comprise aspinneret plate having a plurality of spinning orifices each with itsown confined space, separated from an orifice plate bearing an orificefor each spinning orifice, by a first metal shim and the orifice platebeing separated from a pack body by a second metal shim, said spinneretplate being urged towards said pack body so as to compress said shimsand the orifice plate into good contact with each other and with saidspinneret plate and said pack body, said shims and said orifice platehaving appropriate apertures cut through their thickness in order toform when assembled the desired distributive ducts for each of thepolymeric constituents of the conjugate filaments from a common sourcefor each of the polymeric constituents to each of the confined spaces.The distributive ducts may be formed in the faces of the spinneret plateor in the face of the pack body or partly in each, and may be fed byfeed passages entering the pack body from the side distance from thespinneret plate.

A specific embodiment of our invention will now be described withparticular reference to FIGS. 1, 2, 3, 4, 5, 6, 7 and 8 wherein FIG. Ishows a vertical section of a multiple spinneret,

FIG. 2 shows a plan of a distributor, shown at (8) in FIG. 1,

FIG. 3 shows a plan of a spinneret, shown as (l) in FIG. 1,

FIG. 4 shows a section of FIG. 3 through A A,

FIG. 5 shows a section of FIG. 3 through B B,

FIG. 6 shows a plan of a shim, shown as (12) in FIG.

FIG. 7 shows a plan of a shim, shown as (13) in FIG.

FIG. 8 shows a plan of an orifice plate, shown as (14) in FIG. 1,

FIG. 9 shows a detail of FIG. 1, not strictly to scale, showingdirection of flow, and including the widening of the confined space atthe point of entry of the second polymer, referred to hereinbefore.

Referring to FIG. 1, a spinneret plate 1 has spinneret apertures 2,communicating by way of a lead-in cone 3 with a confined space 4. Afirst entry aperture 5 communicates with the confined space 4 and, byway of a connecting passageway 6, with a central molten polymer feedduct 7, formed in a distributor 8 and fed by a feed pipe 18 of 0.125inches diameter, to which the spinneret plate 1 is urged when theapparatus is assembled. A second feed aperture 9, situated to one sideof the first aperture 5, communicates with the confined space 4 and, byway of a connecting passageway 10, with one of two outer molten polymerfeed ducts 11, formed partly from the spinneret plate 1 and partly fromthe distributor 8. The connecting passageways 6 and 10 serve as meteringpassageways for the molten polymers.

In a particular embodiment of the apparatus according to FIG. I, thefirst and second entry apertures are formed by an orifice plate 14, oflength 3.122 inches, width 1.62 inches and thickness 0.020 inches, ofstainless steel, and shims 12 and 13 of aluminium, and each of thickness0.005 inches. The apparatus is assembled as shown in FIG. 1 and thespinneret plate 1 urged (by means not shown) towards the pack body (notshown), which lies above the distributor 8 and in face contact with it,with formation of a liquid tight joint between the contacting faces ofspinneret plate 1 and shim 13, between shim l3 and orifice plate 14,between orifice plate 14 and shim 12, between shim 12 and thedistributor 8 and between the distributor 8 and the pack body (notshown).

In the orifice plate 14 (and also FIG. 8) the distance x between rows oforifices is 0.437 inches. The orifices 5 are each of 0.009 inchesdiameter. The alignment holes 16 are each of 0.125 inches diameter andwith centres 2.25 inches apart. The molten polymer feed holes 17 areeach of diameter 0.125 inches and with centres 0.808 inches apart.

In FIG. 1, taken together with FIG. 8, the first entry aperture 5 isshown as circular and centrally disposed with respect to thecross-section of the confined space 4. The first entry aperture 5 may,however, be of noncircular cross-section and may further beeccentrically disposed with respect to the cross-section of the confinedspace 4. By such variation of the disposition of the first entryaperture 5 in relation to the centre line of the confined space 4, thecross-section of the core of the filament produced by the apparatus andthe relative disposition of the cross-section of the core with relationto the cross-section of the filament produced can be varied.

The apparatus depicted in FIG. 1, taken together with HO. 8 in generalleads to the production of very eccentric sheath/core filaments.

Our invention is particularly applicable to the manufacture ofsheath/core conjugate filaments of which each of the components is apolyester, a polyamide or a polyolefine.

The apparatus according to the particular embodiment was used for themelt-spinning of sheath/core filaments of poly(ethylene terephthalate),the central polymer feed duct 7 being fed with molten poly(ethyleneterephthalate) of intrinsic viscosity 0.47 as measured on a l g. per lOOml solution in orthochlorophenol at 25C and the second feed aperture 9being fed with poly(ethylene terephthalate) of intrinsic viscosity 0.67.The resultant molten threadlines showed no significant tendency towardskneeing. The filaments were very eccentric sheath/core filaments whichafter drawing and heat relaxing showed marked crimp formation.

We claim:

I. An apparatus for spinning a plurality of eccentric sheath/coreconjugate filaments comprising a spinneret plate having a plurality ofspinning orifices each with its own confined space, separated from anorifice plate bearing an orifice for each spinning orifice, by a firstmetal shim, and the orifice plate is separated from a pack body by asecond metal shim, said spinneret plate being urged towards said packbody so as to compress said shims and the orifice plate into goodcontact with each other and with said spinneret plate and said packbody, said shims and said orifice plate having appropriate apertures cutthrough their thickness in order to form when assembled the desireddistributive ducts for each of the polymeric constituents to each of theconfined spaces.

1. An apparatus for spinning a plurality of eccentric sheath/coreconjugate filaments comprising a spinneret plate having a plurality ofspinning orifices each with its own confined space, separated from anorifice plate bearing an orifice for each spinning orifice, by a firstmetal shim, and the orifice plate is separated from a pack body by asecond metal shim, said spinneret plate being urged towards said packbody so as to compress said shims and the orifice plate into goodcontact with each other and with said spinneret plate and said packbody, said shims and said orifice plate having appropriate apertures cutthrough their thickness in order to form when assembled the desireddistributive ducts for each of the polymeric constituents to each of theconfined spaces.